Microstructure and acoustic property of windmill leaf sheath, fruit bunch and leaf fiber materials

Abstract

The morphology, physical structure and sound absorption performance of fiber materials extracted from windmill palm leaf sheath, fruit bunch and leaf material were analyzed by ultra-depth and electron microscopy, density gradient method, through-pore size analyzer and wave tube methods. The results show that these three elementary palm fibers are spindle-shaped with different length, fineness and hollowness. The fruit bunch fiber has the thickest diameter and lowest density of 20.56 μm and 1.31 ± 0.02 Kg m−3, respectively. The leaf sheath fiber nonwoven materials have the most uniform pore size distribution with the smallest size of 14.0 μm, which is less than one-half size of the leaf fiber nonwoven material. The sound absorbing performance of the leaf sheath nonwoven material is the best among three materials. When the surface density is 0.15 g cm−2, the sound absorption coefficient of leaf sheath, fruit bunch and leaf nonwoven materials reaches its best of 0.40, 0.37and 0.38, respectively. The Miki model has the highest fitting correlation to the sound absorption performance of materials.